Food products, such as pasta, beans, corn peas, other fruits and vegetables, and other types of food products, are processed by blanching or cooking and thereafter cooling then so that the food product can be packaged and shipped. These food products are processed continuously in this manner in rather large volumes in the commercial food processing industry using blanchers and chillers or coolers.
In blanching or cooking food product, food product is introduced into an inlet end of a tank containing heated water and a rotating auger transports the food product toward an outlet or discharge end. As the food product moves from the inlet end of the tank toward the outlet end, its residency time in the tank is carefully controlled to ensure it is properly blanched or cooked.
In cooling or chilling food product, food product is introduced into an inlet end of a tank containing cold or chilled water and a rotating auger urges the food product toward an outlet end. As the food product moves from the inlet end toward the outlet end, its residency time is also carefully controlled to ensure the food product is adequately cooled to a desired temperature.
To increase the volume of food product that can be processed, as well as decrease the residency time within the blancher or the chiller, various mechanisms and methods have been employed to increase the rate of heat transfer between the water and the food product. These heat transfer efficiency enhancing mechanisms and methods can also advantageously enable the size of the food processing equipment to be reduced thereby saving valuable manufacturing floor space.
For example, in Zittel, U.S. Pat. No. 4,875,344, cold or chilled water is introduced into the tank at the outlet end and removed from the tank at the inlet end, creating a flow of water that is opposite in direction to the direction of the flow of food product in the tank for improving cooling efficiency. To further improve cooling efficiency, air manifolds at the bottom of the tank introduce air into the cold water inside the tank to help mix and prevent temperature stratification of the water. As air bubbles upwardly from the tank bottom, it creates turbulence in the water and agitates the water and food product further enhancing heat transfer between the food product and water.
As disclosed in Zittel, U.S. Pat. No. 5,133,249, steam and air are selectively injected into water in the tank from a manifold at the bottom of the tank of a blancher to increase heat transfer between the food product and water, speeding cooking time and also increasing the flow rate of food product through the blancher.
Another mechanism for improving heat transfer in both blanchers and coolers and chillers is lifting or agitating baffles disclosed in Zittel, U.S. Pat. Nos. 4,875,344; 5,133,249; 5,327,817; and 5,456,091. These baffles are located between adjacent flights of the auger and engage and lift food product as the auger rotates thereby agitating the food product. As is shown more clearly in FIG. 6 of U.S. Pat. No. 5,327,817, each baffle located between adjacent auger flights is of planar or straight construction and extends radially inwardly from adjacent a radially outwardly located perforated cylinder screen. At its radially inwardly extending end, each baffle has a downturned straight lip for helping to prevent food product from falling between the baffle and screen. To further help agitate food product, FIG. 6 also discloses straight agitating baffles that extend radially outwardly from a central core of the auger.
Additionally, it is known to attach elongate rods that extend outwardly from a baffle for separating food product to more fully immerse the food product in the water in the tank. By more fully immersing the food product in the water, heat transfer efficiency is improved.
Although both of applicants' baffle arrangements described above have enjoyed substantial commercial acceptance and success, improvements nonetheless remain desirable. For example, certain kinds of food product, such as pouched food products, are more susceptible to being damaged by impact with another object, such as a lifting or agitating baffle. Additionally, it is always desirable to further increase heat transfer to or from food product by baffle agitation or by separating food product.
What is needed is a baffle construction that minimizes the force of impact with food product or pouched food product for minimizing and substantially preventing food product and pouch damage. What is also preferably needed is a baffle construction that agitates food product, as well as the water in the tank, for helping to maximize heat transfer efficiency.